Our focus is on developing approaches to study problems of gastrointestinal toxicology and function. Of particular interest are areas that represent unknowns in the field of intestinal absorption and metabolism, and in the responses related to oral exposure to toxins. Current examples of these areas are the preferential use of energy sources by the isolated intestinal absorptive cells, the regulation of intestinal glucuronidation and sulfation, and the organ specificity of colon carcinogens. The mechanics of these processes are examined necessarily at the cellular, subcellular and molecular levels.